Scintillation loss in optical low earth orbit data downlinks with avalanche photodiode receivers

Giggenbach, Dirk; Moll, Francesc

doi:10.1109/icsos.2017.8357220

Cited by 21 publications

(19 citation statements)

References 19 publications

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“…This simplification is valid in our analysis, because our focus is on the comparison between SISO and MIMO and both the SISO and the MIMO link are similarly affected by these losses. A detailed estimation of effects from atmospheric influence has been shown in the literature (Andrews and Phillips, 2005;Giggenbach and Moll, 2017) and its repetition here would deviate from the actual goal of the paper.…”

Section: Simulation Parametersmentioning

confidence: 84%

A Laser Link From Lunar Surface Employing Line-of-Sight MIMO

Schwarz¹,

Giggenbach²,

Knopp³

et al. 2021

Front. Space Technol.

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Future exploration of our planetary system relies on the Moon as a base and stepping stone to other planets. A high-rate data connection to this celestial body is, therefore, imperative. Free-space optical (FSO) communications will enable continuous broadband connectivity to Earth. Currently pursued concepts incorporate data relay satellites orbiting the Moon, where each individual satellite terminal has to overcome the lunar distance facing restraints on telescope apertures and on beam pointing and tracking accuracies. We propose a concept of one dedicated link originating from a robotic telescope station installed on the lunar surface. We study the conceptual architecture of such an FSO ground node at the lunar surface with a spotlight on the link design at the physical layer. In particular, we increase the FSO channel capacity through multiple transmission- and receiving-apertures. Our findings encourage the application of the Line-of-Sight (LOS) multiple-input multiple-output (MIMO) technology to FSO communications at large link distances typically coming along with space missions, as thereby the maximum MIMO capacity can be achieved. Directing our study on the link geometry such connections seem technically feasible at relatively low system complexity with the receivers located at a single site and the transmitters only few meters apart.

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Section: Simulation Parametersmentioning

confidence: 84%

A Laser Link From Lunar Surface Employing Line-of-Sight MIMO

Schwarz¹,

Giggenbach²,

Knopp³

et al. 2021

Front. Space Technol.

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“…5° is used as minimum and zenith as maximum elevation, and 15° is the typical mean elevation taking into account typical satellite visibilities above ground stations, as calculate elsewhere [5]. Scintillation loss as depicted in [9]…”

Section: Leo Downlink Geometrymentioning

confidence: 99%

Implementation of variable data rates in transceiver for free-space optical LEO to ground link

Pacheco-Labrador

Shrestha

Molina

et al. 2020

Environmental Effects on Light Propagation and Adaptive Systems III

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FSO systems present many advantages like high data rate, license-free bandwidth and tap-proof communication allowing the download of vast amounts of data from LEO satellites. However, the atmospheric channel is quite challenging, because of spurious effects such as absorption, scattering and scintillation that in turn vary the link losses in correspondence to the elevation. In order to maximize the downlink throughput, it should start around 5° elevation. This leads to a design with suboptimal performance for higher elevations when constant data rates are used. Therefore, DLR is developing a system to adjust the data rate according to elevation and atmospheric channel conditions. This data rate variation is achieved by determining the maximum rate for higher elevation and then for lowering the data rates a bit-level repetition is performed. The presented system enables a fast transition between the different data rates. Additionally, this system allows the satellite to transmit data at rates even lower than those nominally supported by the physical transceiver. At the receiver side, the system complexity increases as it should be able to acquire, detect, and filter the signal for different data rates. DLR proposes a system that mirrors the operation of its transmitter counterpart by sampling the acquired signal at the maximum data rate. Then an FPGA processes the signal by majority decision algorithm followed by voting system that filters and detects the intended data rate in real-time. This enables replication and parallelization of the filtering and detection processes enabling the automatic detection of the received data rate. In order to provide noise stability, the transition between data rates is governed by a hysteresis process. This scheme allows the detection and selection of the proper data rate in the range of few microseconds for a system operating between 10 Gbps and 1.25 Gbps in steps of factor of 2, ignoring the propagation delays.

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“…The first two components are elevation-dependent, and measured values are found in [9] for 847 nm wavelength or [10] for 1550 nm, and in [11] a comparison of measured with modelled values is shown. Further measurement data are given in [12].…”

Section: A Parameters For Oleodte-channel Estimationmentioning

confidence: 99%